Sieves or screens



March 13, 1962 A. A. TUNLEY SIEVES OR SCREENS Filed Aug. 24, 1959 3Sheets-Sheet 1 wllli iwr W? 4,44% M,MWW

March 13, 1962 A. A. TUNLEY 3,024,744

SIEVES OR SCREENS Filed Aug. 24, 1959 3 Sheets-Sheet 2 March 13, 1962 A.A. TUNLEY SIEVES OR SCREENS 3 Sheets-Sheet 5 Filed Aug. 24, 1959 niteStates atent 3,924,744 Patented Mar. 13, 1962 3,024,744 SIEVES ORSCREENS Allan Ashrnead Tunley, Peterburough, England, assignor to BakerPerkins Limited, Peterborongh, England Filed Aug. 24, 1959, Ser. No.835,570 Claims priority, application Great Britain Aug. 23, 1958 6Claims. (Cl. 10744) This invention relates to a sieve or screenconstruction of the type in which the sieve or screen is formed by anarrangement of bristles or brush tufts. Sieves or screens of thisconstruction are found, for example, in machines for separating castsweets, such as peppermint creams, from the powdered starch in whichthey are cast, the sweets being carried over the sieve or screen byvibration and the starch falling through the spaces between the bristlesor brush tufts.

It has been previously proposed to employ bristles or brush tufts toform sieves or screens for the confectionery purpose mentioned above byarranging lines of brush tufts (formed by bristles) at an acute angle tothe sieve or screen surfaces in overlapping relationship analogous tothe reeds of a thatched house.

It is an object of the present invention to provide an improved oralternative construction of sieve or screen employing bristles or brushtufts, which is cheaper and quicker to manufacture and which gives animproved through-pass of the sieved or screened-oif material.

It is a further object of the present invention to provide an improvedor alternative construction of sieve or screen employing bristles orbrush tufts, which enables bristle or brush tuft replacement to becarried out quickly and easily.

The invention consists in a sieve or screen incorporating brush means asthe sieving or screening medium in which each brush means comprisesbristles or brush tufts extending generally radially of abristle-supporting spine and spaced therealong and shaped so as toprovide a brush of generally cylindrical form, a plurality of such brushmeans being mounted on a sieve or screen frame with their spines inspaced parallel or substantially parallel relationship such that thebrush bristles of one brush means are in contact with, or overlap thebristles of the adjacent brush means.

According to a preferred form of the invention, as set out in thepreceding paragraph, the bristles of each brush means extend along thebrush spine in a closely pitched helical path. Thus, for example, eachbrush means may be formed, in known manner, by forming the brush spinefrom two or more metal wires or rods having brush bristles distributedevenly therebetween and at right angles to the wires or rods andtwisting the Wires or rods around each other to trap the bristles andlocate them on a helical path.

The invention further consists in a sieve or screen as set out abovewherein the spine of each brush means extends beyond the terminalbristles to provide spigots for mounting the brush means in the frame.According to one convenient construction, the frame comprises two spacedparallel longitudinal members joined across at their ends into arectangular frame by transverse members and a central bearer spanningthe distance between the longitudinal members spaced equidistantly fromboth the transverse members, and the space on each side of the centralbearer is filled with brush means, as set out above, by providingapertures along the central bearer spaced at intervals equal to orslightly less than the radius of a brush means and having their axes in,or par allel to, the plane of the frame, and apertures along thetransverse members spaced at intervals equal or slightly less than thediameter of a brush means and having their axes transverse to the planeof the frame, the brush means spigots, formed by the projecting spinesof the brush means at one end, engaging alternately from opposite sidesthe apertures in the central bearer, and the spigots at the other endbeing downturned to engage in the ap rtures in the transverse members.By suitable spacing of the apertures in the central bearer and in thetransverse members, the bristles of each brush means may be made totouch or overlap the bristles of the adjacent brush means.

A plurality of such sieve or screen frames may be assembled, for examplein line with their transverse members adjacent, means such as aperturesbeing provided, for receiving additional brush means to bridge the gapbetween the two frames.

As a modification to the above described mode of mounting the brushmeans in the frame, the outward spigots or spindles of the brush meansare not turned down but are received in apertures in the transversemembers co-axial with those in the central bearer, so that the brushmeans may be turned, if required, on their axes, means such as flangesor set screws being provided to keep the brush means in place.

In the case of a sieve or screen for use in a machine for separatingstarch from cast sweets as mentioned above, where it is usual to employsieves or screens which are downwardly slightly concave, the sieve orscreen construction according to the present invention has particularutility since the brush means may be disposed so as to extend at rightangles to the concavity of the sieve or screen so that straight brushmeans may be employed, the concave section being obtained by forming thetransverse members and central bearer of each frame with the desiredcurvature in elevation.

In the accompanying drawings:

FIGURE 1 is a plan view of a sieve or screen frame in which the sieve orscreen is formed by a plurality of brush means, according to the presentinvention,

FIGURE 2 is an end elevation of the sieve or screen frame and brushmeans shown in FIGURE 1,

FIGURE 3 is a side elevation of one of the brush means forming the sieveor screen in FIGURE 1,

FIGURE 4 is a sectional view taken on the line 4-4 of FIGURE 1,

FIGURE 5 is a fragmentary plan view of a sieve or screen frame having asieve or screen formed by a modified construction of brush means, and

FIGURE 6 is a side elevation of one of the modified brush means shown inFIGURE 5.

In carrying the invention into effect according to one mode by way ofexample the sieve or screen comprises a framework made up oflongitudinal tubular members I linked at each end by transverse members2, preferably of flat strip section. The transverse members 2 may becurved as shown in FIGURE 2 so as to provide a sieve or screen having aconcave face for use in known manner in confectionery casting machines.In the centre of the framework, parallel to and between the transversemembers 2 is a central bearer member 3 which is preferably of stripsection and disposed on edge.

The sieve or screen itself is provided by a plurality of cylindricalbrushes 4, the bristles 5 of which extend generally radially from acentral rigid spine 6. Conveniently the brushes 4 are made up, in knownmanner, by placing bristles between two or more straight wires or rodsand twisting the latter about a common axis so that the bristles aretrapped and located on a. helical path as shown in the drawings.

The brushes 4 are located in the framework so that they extend parallelto the longitudinal members 1 and are spaced so that the bristles of onebrush touch those of the adjacent brush or brushes, see FIGURE 1.Alternatively the brushes 4 may b spaced still closer so that thebristle tips of adjacent brushes overlap.

According to one convenient mode of mounting the brushes 4 in the abovemanner in the framework, the spine 6 of each brush is extended at eachend beyond the termination of the bristles to provide spigots 7 and 8 ofwhich the spigot 8 is preferably bent at right angles to the axis of thespine 6 (see FIGURES 3 and 4) so as to prevent turning of the brush whenmounted as will be described. The central member 3 of the framework isformed with apertures 9, see FIGURE 4, each spaced apart by a distanceequal to half the spacing between successive brushes 4 on either sid ofthe central member 3 and the straight spigot ends 7 of the brushes 4pass through the apertures 9 from alternate sides of the central member3 to locate and secure the inward ends of the brushes 4. Thus the axesof the spines 6 of the brushes 4 on one side of the central member 3 arestaggered with respect to those on the other side. The transversemembers 2 at each end of the framework are formed wtih apertures 10,

see FIGURE 4, extending at right angles to the axes of the apertures 9in the central member 3', and the apertures 10 are spaced apart by adistance equal to the pitch between successive brushes 4 and accommodatethe down-bent spigot ends 8 of the brushes 4 to locate and secure theoutward ends of the brushes 4 and prevent the brushes from turning. Inorder to lock the brushes 4 in place the extreme end 11 of the bent-downspigot ends 8 are bent over as shown in FIGURE 4.

In an alternative embodiment of the invention, see FIGURES and 6, thesieve framework is substantially the same as already described, but thespines 6a of the brushes 4a are lengthened to provide an extendedportion 7a, free of any bristle. Thus, in FIGURES 5 and 6 the portion ofeach brush 4a to the left of th central member 3 is equipped withbristles 5a formed as before and the spine portion 7a of each brush tothe right of the central member 3 is bare. The two ends of the spine 6aare downturned into spigot portions 8a which are received, as describedpreviously, in apertures in the transverse members 2. By thisarrangement the bare portions 7a of each brush lie between theperipheries of the bristle portions 5a of the two adjacent brushes andserve further to inhibit the passage of unwanted material through thesieve or screen.

In order to strengthen and stabilize the brush structure forming thsieve or screen, binding wires 12 or the like may be successively lacedround the brush spines 6 or 6a, although this has only been shown inFIGURES 5 and 6 for the brush spines 6a.

Where the sieve or screen means, according to the present invention areto be used end-to-end to provide a sieve or screen of extended length,as in a confectionery casting machine, the sieve or screen may beextended over the junction between one framework and the next by theprovision of special end brush lengths 13, hearing bristles 14 alongtheir entire length and securable substantially over the transversemembers 2 of each frame. The spine 15 of each end brush 13 is downturnedto provide fixing and locating spigots 16 receivable in apertures 17 atthe junction of the longitudinal members 1 and transverse members 2.

I claim:

1. A sieve or screen incorporating brush means as the sieving orscreening medium in which each brush means comprises bristles extendinggenerally radially of and around a bristle-supporting spine and spacedtherealong and shaped so as to provide a brush member of generallycylindrical form, a plurality of such brush means being mounted on asieve or screen frame with their spines in spaced parallel orsubstantially parallel relationship such that the brush bristles of onebrush means are in contact with the bristles of the adjacent brushmeans, the spine of each brush member extending beyond its bristles toprovide spigots for mounting the brush members on the frame.

2. A device as claimed in claim 1, wherein the frame comprises twospaced parallel longitudinal members joined across at their ends into arectangular frame by transverse members and a central bearer spanningthe distance between the longitudinal members spaced equidistantly fromboth the transverse members, and wherein the space on each side of thecentral bearer is filled with said brush members, said central bearerhaving apertures spaced apart at intervals no greater than the radius ofa brush member and having their axes in the plane of the frame, saidtransverse members having apertures spaced at intervals no greater thanthe diameter of a brush member and having their axes transverse to theplane of the frame, the spigots at the ends of the brush membersadjacent said central bearer engaging alternately from opposite sidesthe apertures in the central bearer, and the spigots at the other endsof said brush members being downturned to engage in the apertures in thetransverse members.

3. A device as claimed in claim 2, wherein the spine of each brushmember is extended, but does not carry bristles, at its non-downturnedend to span the space on the side of the central bearer opposite to thatspanned by the bristle-bearing portion of the brush, the arrangementbeing such that between the bristles of adjacemt pairs of brush memberson either side of the central bearer the non-bristle-bearing spinesection of a brush member on the other side of the central bearer isinterposed to inhibit further the passage of unwanted material throughthe device.

4. A device as claimed in claim 1, wherein flexible tie means aresuccessively laced round the spines of said brush members from onelongitudinal member to the other in order to strengthen and stabilizethe brush members.

5. A device as claimed in claim 1 including transverse cylindrical brushmeans extending over the width of the frame at right angles to saidbrush members and located over each transverse member such that when twosimilar frames are located end-to-end, the transverse brush means ofeach frame inter-engage to screen the junction between the two frames.

6. A sieve or screen device comprising frame means; a plurality ofgenerally cylindrical brush members each composed of a spine andbristles secured to and radiating from said spine; and means mountingsaid brush members non-rotatably on said frame in substantially parallelrelation with the bristles of said brushes in contact with one another,said bristles providing'a supporting surface for articles.

Dye Sept. 15, 1925 Rapisarda Oct. [22, 1935

